We cut & finish each pole to your requirements. Just measure your window, add space either side to stack the curtains (usually 15 to 30cm), and check that you have space for the finials. Finials other than the Disc include a sleeve that slides on to the end of the pole by 2.5cm. The measurement you supply is the measurement between the finials, so we add 5cm to allow for the pole that slides inside the finials. Bracket length is the distance from the wall to the centre of the pole. For information about GripIt® plasterboard fixings please see the Gripit® website.